doi: 10.21495/5896-3-302 26 th International Conference ENGINEERING MECHANICS 2020 Brno, Czech Republic, November 24 – 25, 2020 PROBABILISTIC ANALYSIS OF MACHINE TOOL STRUCTURES FRAGILITY ON EXTREME SNOW IMPACT Králik J. * Abstract: This probabilistic assessment of NPP structures for Probabilistic Safety Analysis (PSA) level 2 of VVER 440/213 in the case of the extreme external even without the earthquake is presented. On the base of the meteorological monitoring of the locality, the extreme load parameters were defined for the return period 104 years using the Monte Carlo simulations. There is showed a summary of calculation models and calculation methods for the probability analysis of the structural resistance. The general purpose of the nonlinear probabilistic analysis of the NPP structure resistance was to define the safety level of the critical structural elements. The numerical simulations on the base of the LHS method were realised in the system ANSYS and FReET. Keywords: Probability, Nonlinearity, Fragility, Extreme snow, NPP, ANSYS, FReET. 1. Introduction This paper deals with the resistance of the steel hale frame of the nuclear power plant (NPP) in the locality of Mochovce. The international organization IAEA in Vienna (IAEA, 2006) set up the design requirements for the safety and reliability of the NPP structures. The extreme environmental events (e.g. wind, temperature, snow, explosion, ...) (Kralik, 2009, 2019 and NUREG, 1992) are the important loads from the point of the NPP safety performance. The extreme loads are defined with the probability of mean return period equal to one per 10 4 years (IAEA, 2006 and Kralik, 2009, 2019). Fig. 1: View to the machine tool structures of the NPP with reactor VVER440/213. 2. Probabilistic assessment Most problems concerning the reliability of building structures are defined today as a comparison of two * Prof. Ing. Juraj Králik, PhD.: Faculty of Civil Engineering STU in Bratislava, Radlinského 11; 810 05, Bratislava; SK, juraj.kralik@stuba.sk 302